Inhibiting dental plaque

ABSTRACT

Inhibiting the formation of dental plaque with a composition comprising about 0.05 to 3 percent by weight of pyromellitic acid in a physiologically acceptable vehicle.

United States Patent Felger [451 June 20, 1972 521 u.s.c| L....424/49,424/317 s1 lnt.Cl ..A6lr7/l6 [58] FieldofSearch..424/49-ss,311

[56] References Cited UNITED STATES PATENTS 3,542,917 I 1/1970 Schwartzet a] ..424/49 Primary Emminer-Richard L. Huff Attorney-R. W. Furlong[57] ABSTRACT Inhibiting the formation of dental plaque with acomposition comprising about 0.05 to 3 percent by weight of pyromelliticacid in a physiologically acceptable vehicle.

19 Claims, No Drawings lNl-lIBITING DENTAL PLAQUE This invention relatesto treating teeth to inhibit the formation of dental plaque.

Dental plaque consists of a dense strongly adherent organic layer thatforms naturally on the teeth, the rate and extent of formation varyingwith the individual. The layer consists of proteinaceous and mucoidmaterial derived not only from saliva and food but also from theresidues of bacterial metabolism. Plaque is a haven for bacteria and isaccordingly undesirable since it can be a contributing cause of caries.It also serves as a matrix for accelerating the formation of undesirablecalculus deposits. If allowed to proliferate, the plaque layer canbecome very unsightly as well as detrimental to dental health.Heretofore, plaque has been controlled only by removing it mechanically,i.e., by frequent vigorous brushing with abrasive dentifrices and/or byprofessionally applied prophylaxis treatments. There is some evidencethat strong bactericides frequently applied can slow down plaqueformation, as might be expected, by reducing the population ofplaque-forming bacteria. Applied with sufficient frequency at effectivedosages, however, the biocidal activity of such compositions could haveuntoward effects.

Accordingly, an object of this invention is to provide compositions forinhibiting formation of dental plaque, which have little or no tendencyto upset the normal balance of oral flora, so that mechanical removal isrequired only at long intervals. More specific objects are to provideplaque-inhibiting mouthwashes, dentifrices, toothpastes, tooth powders,and the like.

The invention features inhibiting the formation of dental plaque withcompositions comprising about 0.05 to 3 percent by weight ofpyromellitic acid in a physiologically acceptable liquid vehicle. Onesuch composition, a dentifrice, contains an effective amount of anabrasive in addition to the acid. Another composition is in a liquidvehicle having a pH of about 3 to 9 (more preferably, about 5 to 7),which contains the equivalent of about 0.2 to 0.5 percent by weight ofpyromellitic acid and a buffering anion. Another preferred compositionis in a liquid vehicle and contains a germicide (preferably, 0.02 to 0.5percent by weight) in addition to the acid.

The pyromellitic acid is conveniently provided in the form of a watersoluble salt of the acid in an aqueous vehicle or in a mixture of waterand one or more water-soluble alcohols, such as a mixture of water andethyl alcohol, in which the alcohol content is up to about 25 percent(preferably between about l5 and percent). The salt is convenientlyprovided in situ by adding pyromellitic acid to a medium containing thecation of a water-soluble salt of the acid.

Although, e.g., mouthwash or dentifrice compositions preferably containbuffering anions, dental plaque may be also removed in accordance withthe invention by topically applying an unbutfered solution ofpyromellitic acid by swabbing. In general, any buffer system may be usedthat buffers efiectively in the pH range, 5 to 7, and is physiologicallyacceptable. Exemplary well-known buffer systems include phosphate,citrate, and phosphate-citrate mixtures, a preferred bufi'er being aconventional mixture of sodium or potassium phosphates.

The useful pyromellitic acid salts are those having a nontoxic inorganicor organic cation which produces a water-soluble salt (at least about 3percent by weight at room temperature). Preferred cations includesodium, potassium, ammonium, alkylol ammonium, and quaternary ammoniumions. Since pyromellitic is a tetracarboxylic acid it can form mono-,di-,tri-, and tetrasalts with these cations, all of which can and doco-exist in solution, the ratio of these salts to each other dependingon the pH and concentration of the solution and the identity of thecation, and not being otherwise critical to the present invention.

The composition may take any of a number of physical forms includingmouthwashes, dentifrices (toothpaste, toothpowder, or tootheleaningliquid) or a liquid such as is used in the pressure-jet method forcleaning teeth (e.g., by a Water Pie). The composition may also beapplied, as above noted, by swabbing onto the tooth surface without anysubstantial brushing or abrasive action. The dosage and duration oftreatment is not critical and depends generally on the form ofcomposition and the concentration of the pyromellitic acid salt. Inaddition to the pyromellitic acid salt, therefore, the composition maycontain other ingredients to render it in a more desirable, or moreapplicable, or more convenient, or stabler physical form, so long asthese ingredients are substantially inert to pyromellitic acid orotherwise not inhibitive of the protective action of the acid.

For example, minor amountsv of other solvents (up to about 10 percent byweight) such as glycerol or a glycol may also be present in the water oraqueous alcohol vehicle. Flavoring agents and sweeteners such aspeppermint oil, oil of cinnamon, saccharin, sorbitol, etc., may also beincorporated in suitable conventional amounts as may any of theconventional physiologically acceptable dyes or coloring agents.Suitable preservatives may also be included. Among the preferredpreservatives are the phenolic type, examples being benzoic acid, theparasepts, hexylresorcinol, thymol, and chlorothymol. Other preferredpreservatives are quaternary ammonium types, such as cetyl pyridiniumchloride, benzylalkonium chloride, and dodecyl dimethyl (2-phenoxyethyl)ammonium bromide (Domiphen bromide"). Should a germicidal formulation bedesired, the concentration of the preservative ingredients can beincreased from the preservative level to the oral germicidallevel. Forexample, whereas 0.05 percent by weight or less of hexylresorcinol isuseful as a preservative, 0.1 to 0.5 percent by weight is preferred forgermicidal purposes. As another example, whereas 0.01 percent by weightor less of cetyl pyridinium chloride is useful as a preservative, 0.02to 0.1 percent by weight is preferred for germicidal purposes.

Surfactants such as sodium lauryl sulfate, sodium lauryl sareosinate orsodium lauryl sulfoacetate, preferably up to about 2 percent by weight,may also be incorporated, particularly in dentifrices. For toothpowderand toothpaste fonnulations, a suitable abrasive, such as calciumpyrophosphate, insoluble sodium metaphosphate, alumina, or calciumcarbonate, is also present. The amount of abrasive may, range, in atoothpaste from 30'to 60 percent by weight, and in a toothpowder from 50to 98 percent by weight.

Other objects, features and advantages will be apparent to one skilledin the art fromthe following non-limiting examples.

EXAMPLE 1 A mouthwash was prepared by dissolving 5 grams of pyromelliticacid and 1 gram of benzoic acid in 1,000 grams of aqueous sodiumphosphate buffer solution having a pH of 6.8. This mouthwash was testedclinically on a group of subjects who used it as their exclusive oralhygiene procedure over a period of 2 weeks. 10 ml was used to rinsethemouth twice per day, the duration of each rinsing being 1 minute. Boththe test subjects and a control group, who rinsed with an identicalcomposition minus the pyromellitic acid, were given an oral prophylaxis(brushing and scraping) to remove plaque immediately prior to the test.At the end. of the test period the plaque which had accumulated on theteeth was measured quantitatively. It was found thatthe group which hadused the pyromellitic acid-containing mouthwash had accumulated about 25percent less plaque on the average than had-thecontrol group.

EXAMPLE 2 A mouthwash was prepared having the following composi'-- tionin parts by weight:

Pyromellitic acid .5 parts Hexylresorcinol .1 parts Ethanol 20 partsSodium hydroxide sufficient to provide pH of 6.2 Water to make up to lparts total EXAMPLE 3 A mouthwash was prepared having the followingcomposition, in parts by weight:

Pyromellitic acid Ethanol Sorbitol Flavoring Coloring Sodium saccharinCetyl pyridinium chloride Sodium hydroxide sufficient to provide pH of6.4

Water to make up to This mouthwash also was tested clinically and foundto be .5 parts parts 8.l parts .05 parts .004 parts .04 parts .003 parts100 parts total effective in inhibiting the build up to dental plaque.

EXAMPLE 4 A germicidal mouthwash for inhibiting dental plaque has thefollowing composition, in parts by weight:

EXAMPLE 5 0.5 parts .l parts 17.95 parts .03 parts .134 parts .038 parts.019 parts .004 parts l00 parts total.

A toothpaste for inhibiting dental plaque has the following compositionin parts by weight:

Calcium pyrophosphate Calcium carbonate Sodium lauryl sulfate GlycerineSorbitol Hydroxyethylcellulose Saccharin Oil of peppermint Pyromelliticacid Sodium hydroxide sufficient to provide pH of 5.5 Water to make upto EXAMPLE 6 20 parts 20 parts 1.5 parts 10 parts 20 parts 1 part .1parts .8 parts .8 parts I00 parts total A toothpowder for inhibitingdental plaque has the following composition in parts by weight:

Calcium pyrophosphate Sodium lauryl sulfate Powdered disodium salt ofpyromellitic acid 96.8 parts 1 part 1 part l part Flavoring .2 partsSodium saccharin Other embodiments will occur to those skilled in theart and are within the following claims.

What is claimed is:

1. A dentifrice composition comprising about 0.05 to 3 percent by weightof l) a member of the group consisting of pyromellitic acid andwater-soluble salts thereof and (2) an effective amount of an abrasivein a physiologically acceptable vehicle.

2. The dentifrice composition of claim 1 wherein said vehicle includes asolvent for said member and has a pH between about 3 and 9.

3. The composition of claim 1 including about 0.2 to 0.5

percent by weight of said member.

4. The composition of claim 1 having a pH between about 5 and 7.

5. The composition of claim 1 including up to 2 percent by weight of asurfactant.

6. The composition of claim 1 wherein said member is in the form of awater-soluble salt of pyromellitic acid.

7. A composition for inhibiting the formation of dental plaquecomprising about 0.05 to 3 percent by weight of l) a member of the groupconsisting of pyromellitic acid and water-soluble salts thereof and (2)a buffering anion, said member dissolved in a physiologically acceptableliquid vehicle having a pH between about 3 and 9.

8. The composition of claim 7 wherein said vehicle comprises water andwater-soluble alcohol.

9. The composition of claim 8 wherein said vehicle includes up to about25 percent ethanol. I

10. The composition of claim 9 wherein said vehicle includes about 15 to20 percent ethanol.

11. The composition of claim 7 having a pH between about 5 and 7.

12. The composition of claim 7 wherein said vehicle includes aneffective amount of a gerrnicide selected from the class consisting ofphenolic and quaternary ammonium type gerrnicides.

13. The composition of claim 12 including about 0.02 to 0.5 percent ofsaid germicide.

14. A composition for inhibiting the formation of dental plaquecomprising about 0.05 to 3 percent by weight of l) a member of the groupconsisting of pyromellitic acid and water-soluble salts thereof, and (2)an effective amount of a germicide, said member dissolved in aphysiologically acceptable liquid vehicle having a pH between about 3and 9.

15. The composition of claim 14 wherein said vehicle comprises water andwater-soluble alcohol.

16. The composition of claim 15 wherein said vehicle includes up toabout 25 percent ethanol.

17. The composition of claim 16 wherein said vehicle includes about 15to 20 percent ethanol.

18. The composition of claim 14 having a pH between about 5 and 7.

19. A process for inhibiting the formation of dental plaque in teethcomprising applying to the teeth a composition comprising about 0.05 to3 percent by weight of l) a member of the group consisting ofpyromellitic acid and water-soluble salts thereof and (2) aphysiologically acceptable vehicle.

2. The dentifrice composition of claim 1 wherein said vehicle includes asolvent for said member and has a pH between about 3 and
 9. 3. Thecomposition of claim 1 including about 0.2 to 0.5 percent by weight ofsaid member.
 4. The composition of claim 1 having a pH between about 5and
 7. 5. The composition of claim 1 including up to 2 percent by weightof a surfactant.
 6. The composition of claim 1 wherein said member is inthe form of a water-soluble salt of pyromellitic acid.
 7. A compositionfor inhibiting the formation of dental plaque comprising about 0.05 to 3percent by weight of (1) a member of the group consisting ofpyromellitic acid and water-soluble salts thereof and (2) a bufferinganion, said member dissolved in a physiologically acceptable liquidvehicle having a pH between about 3 and
 9. 8. The composition of claim 7wherein said vehicle comprises water and water-soluble alcohol.
 9. Thecomposition of claim 8 wherein said vehicle includes up to about 25percent ethanol.
 10. The composition of claim 9 wherein said vehicleincludes about 15 to 20 percent ethanol.
 11. The composition of claim 7having a pH between about 5 and
 7. 12. The composition of claim 7wherein said vehicle includes an effective amount of a germicideselected from the class consisting of phenolic and quaternary ammoniumtype germicides.
 13. The composition of claim 12 including about 0.02 to0.5 percent of said germicide.
 14. A composition for inhibiting theformation of dental plaque comprising about 0.05 to 3 percent by weightof (1) a member of the group consisting of pyromellitic acid andwater-soluble salts thereof, and (2) an effective amount of a germicide,said member dissolved in a physiologically acceptable liquid vehiclehaving a pH between about 3 and
 9. 15. The composition of claim 14wherein said vehicle comprises water and water-soluble alcohol.
 16. Thecomposition of claim 15 wherein said vehicle includes up to about 25percent ethanol.
 17. The composition of claim 16 wherein said vehicleincludes about 15 to 20 percent ethanol.
 18. The composition of claim 14having a pH between about 5 and
 7. 19. A process for inhibiting theformation of dental plaque in teeth comprising applying to the teeth acomposition comprising about 0.05 to 3 percent by weight of (1) a memberof the group consisting of pyromellitic acid and water-soluble saltsthereof and (2) a physiologically acceptable vehicle.